Geoege pilson



(No Model.)

G. PILSON.

SAFETY DOG-FOR ELEVATORS.

Patented May 29,1888.

INVENTOR WITNESSES ATTORNEYS.

bSO

' UNITED STATES PA ENT OFFICE.

GEORGE PI'LSQN, OF YOhlKERS, NEW YORK.

SAFETY-Doe FOR LEVA ORS.

SPECIFICATION forming part of Letters Patent No. 278,595, dated May 2 9, 1883.

Applicationfiled April 14, 1883. (No model.)

prevent the car from being dashed against the bottom of the shaft.

The invention consists in sliding dogs provided with threaded apertures, into which the threaded ends of a shaft in thecar pass,which shaft is surrounded by a coiled spring, which is released by means of a cord passing'arouud the-cable-drums with the cablewhen the cable breaks, whereby the said spring will uncoil and revolve the shaft, thereby moving the dogs or blocks outward from the sides of the of vertical racks in the elevator-well.

Reference is to be had to the accompanying drawings, forming part of this specification, in which similar letters of reference indicate corresponding parts in both the figures.

Figure 1 is a longitudinal sectional elevation of an elevator-car provided with my improvement. Fig. 2 is a detail cross-sectional elevation on the line at as, Fig. 1.

A shaft, A, is journaled in hangers B on the ceiling or top of theframe of an elevatorcar, 0, and to the said 'shaft one end of a spiral spring, D, is fastened, which spring is coiled around the shaft, and has its other end secured to a casing, E,surroundingthe spring, which casing is held to a rod or bracket, F, projecting from the ceiling or top of the car. On the shaft A aratchet wheel, G, is rigidly mounted, adjoining the casing E, with which ratchet-wheel a pawl, H, engages, which ispivoted to the casing E. The shaft A is pro 'vided with one or more collars, J, having apertures a, for introducing rods or keys for rotating the shaft A to coil the spring D or th'eshaft can be provided with any other suitable devices for applying a key for turning the shaft. The ends of the shaft A are provided with opposite screw-threads, and screwed carrand causing them to engage with the teeth- Patent, is-

into apertures in the inner ends of sliding dogs or blocks K, having their outer ends Dev eled downward, which dogs are adapted to slide outward from the sides of the car and to engage with vertical racks L. secured on the sides of the shaft. A cord, M, attached to the pawl H, passes over the pulley with the main cable N, and is wound and unwound with the same; or the cord M can pass through suitable eyelets or guides in the car, so that it can be pulled by persons in the car.

The operation is as follows By turning the shaft A to wind up the spring D, the threaded ends of the shaft A are screwed into the threaded apertures in the blocks or dogs K, whereby the said blocks will be drawn inward and will be held in the position shown in Fig. 1. If the cable N breaks the cord M will pull the pawl H upward, thereby releas' ing the spring 1), which immediately uucoils, thereby rotating the shaft A in such a manner that the threaded ends of the same are screwed out, of-the blocks or dogs K, whereby the said dogswill be forced outward and between the teeth of the racks L, with which they engage,

thereby holding the elevator-car in place and Asstated, the cord M can be so arranged that it can be pulled by a person iuthe car in case the descent of the car is to be stopped.

Having thus described my in vention,what I claim as new, and desire to secure by Letters 1. The combination, with an elevator-car,of

laterally-sliding dogs, and a shaft provided with opposite screw-threads at the ends for operating the said dogs, substantially as herein shown and described, and for the purpose set forth.

2. The combination, with an elevator-car, of laterally-sliding dogs, aoshaft provided with opposite screw-threads engaging with screwthreads on the dogs, and of a spring for revolving the said shaft to throw the dogs out.- ward, substantially as herein shown and described, and for the purpose set forth.

3; The combination, with an elevator-car, of the sliding dogs K, the shaft A, having oppoand the' collars J, for turning the shift to eoil the spring D, substantially as herein shewn I0 and described, and for the purpose set forth.

GEORGE PILSON.

site screwthreaded ends, the spring 1), the casing E, the ratchet-wheel G, and the pawl H, substantially as herein shown and described, and for the purpose set forth.

4. The'combination, with an elevator-car, of the sliding dogs K. the shaft A, having qpposite screw-threaded ends, the spring D, the casing E, the ratchetheel G, the pawl H,

Witnesses:

JOHN H. KEELER, HENRY M. ANDERSON. 

